Split shed dobby for loom



April 10, 1956 E. R. HOLMES SPLIT SHED mossy FOR LOOM 2 Sheets-Sheet 1 Filed April 15, 1953 lIilIll||IllIIIIIIlIIIIIIIIIII|IlllIIIIIIIIIIIIIIIIllllllllflllll INVENTOR ELBRIDGE R. HOLMES VI E N R O T T A April 10, 1956 E. R. HOLMES 2,741,271

SPLIT SHED DOBBY FOR LOOM Filed April 15, 1953 2 Sheets-Sheet 2 FIG. ll

20 mum-m N mm! 56 FIG. 7

20 nu-m mum! raw-m mum-m INVEN TOR ELBRIDGE R. HOLMES ATTORNEY Unite SPLIT snnn nosnv son LooM Elbridge R. Holmes, Worcester, Mass, assignor to Crampton & Knowles Loom Works, Worcester, Mass, a corporation of Massachusetts Application Aprii 15, 1953, Serial No. 348,977 19 Claims. (Cl. 139-41) This invention relates to dobbies for looms and it is the general object of the invention to provide a dobby which will split the shed and thereby avoid objectionable crowding of warp threads in the reed dents as the threads pass each other to form a new warp shed.

The usual dobby includes oppositely reciprocating knives to actuate hooks connected to back levers which are pivoted to harness frame lifting jacks. When the jacks shift position to change the warp shed they operate in such manner that all the moving Warp threads in the reed pass each other at substantially the same time with the result that if the warp is heavy and there are several threads per reed dent the warp threads can injure each other as they pass, and can also delay the complete opening of the warp shed. I

It is an important object of the present invention to provide means for correcting these objections including an operating lever actuated by the knives and having pivoted to it a harness lever acted on by control means which rocks the harness lever at a rate different from that of the regular jacks so that the warp threads controlled by the harness lever will be either ahead of or behind the threads which are controlled by the regular jacks when they cross.

It is a further object of the invention to make the aforesaid control mechanism rock the harness ever first in one direction with respect to the operating lever during part of the motion of the latter and cause the harness lever to rock in the opposite direction with respect to the operating lever during another part of the motion of the operating lever.

It is a still further object of the invention to make the control mechanism for the harness lever of two members one of which may be a cam and the other of which may be a roll to engage the cam. The cam may be either on the harness lever, in which case the roll will turn about a stationary axis, or the cam may be a normally stationary part of the dobby, in which case the roll will be carried by the harness lever. Furthermore, the cam may be either convex or concave toward the roll depending upon the character of motion desired for the harness lever relative to the harness jacks.

It is another object of the invention to make the control mechanism in the form of a link one end of which is pivoted to the harness lever and the other of which moves about a pivot fixed with respect to the dobby so that as the operating lever moves the harness lever the link will first rock the harness lever in one direction and thereafter rock the lever in the opposite direction relative to the operating lever during a Working stroke of the latter.

In order that the invention may be readily adapted to existing dobbies it is a further ject of the invention to mount either the cam member or the roll member, whichever is supported on the dobby, so it can be swung down 2,741,271 Patented Apr. 10, 1956 to a position where it will not interfere with the removal either of a jack of the ordinary type or of the type more particularly forming the subject matter of this invention.

In order that the invention may be clearly understood reference is made to the accompanying drawings which illustrate by way of example five embodiments of the invention and in which:

Fig. l is a diagrammatic front elevation of part of a loom having the preferred form of the invention ap plied thereto,

Fig. 2 is an enlarged front elevation of part of the structure shown at the upper left hand part of Fig. 1, part of the structure being in cross section,

Fig. 3 is a horizontal section on line 3-3, Fig. 2,

Fig. 4 is an enlarged horizontal section on line 44 through one of the harness levers,

Fig. 5 is a diagrammatic view illustrating the operation of the preferred form of the invention,

Fig. 6 is a fragmentary view similar to the lower part of Fig. 2 illustrating the first modified form of the invention, I

Fig. 7 is an enlarged horizontal section on line 77, Fig. 6,

Fig. 8 is a view similar to Fig. 6 but showing the sec- 0nd modified form of the invention,

Fig. 9 is an enlarged horizontal section on line 9-9, Fig. 8,

Fig. 10 is a view similar to Fig. 6 but showing the third modified form of the invention,

Fig. 11 is an enlarged horizontal section on line 11-11, Fig. 10,

Fig. 12 is a view similar to Fig. 6, but showing the fourth modification, and

Fig. 13 is an enlarged horizontal section on line 13 13, Fig. 12.

Referring more particularly to Figs. 1 and 2, the loom frame 1 supports a dobby, designated generally at D, for controlling the vertical position of the warp controlling harness frames. These harness frames are normally pulled down by springs 2 and are lifted against the action of the springs by harness cords 3. These cords are connected at their left hand end as viewed in Fig. l to regular jacks or lever units to be described which rock during the operation of the dobby. In Fig 1 two harness frames 4 and 5 in rear position operate in usual manner.

Much of the dobby is of usual construction and employs top and bottom actuator knives 6 and 7 respectively for top and bottom hooks 8 and 9.. These hooks are connected in pairs to dobby back levers 1i) certain of which are pivoted at it to the ordinary or regular harness jacks 12, such as operate frames and 5. The dobby includes front and back side plates 13 and 14 which support a pivot rod 15 extending across the dobby. The regular jacks 12 have open bearings 16 which fit over the rod 15 which limit movement of the lower ends of the jacks in a left hand direction as viewed in Fig. 2, but permits the jacks to be removed by a right hand motion under conditions to be described. In Fig. 2 two of the regular jacks, indicated at 12a and 112b, correspond respectively to harness frames 4 and 5.

During the operation of the dobby the knives 6 and 7 are reciprocated by Well-known mechanism (not shown) in opposite directions, the top knife moving out or to the left as the bottom knife moves to the right, and vice versa. The position of the hooks 8 and 9 is determined by pattern mechanism (not shown) and some of these hooks will be engaged by' their respective knives while others will be above their knives. Any hook which is engaged by its knife when the latter has a working stroke,

' heavy and all of the harness frames in the to the left, Fig. 1, will roclsits back lever lit to cause 'movement of the associated regular jack from a right hand position to a left hand position, or from the position occupied by jack lZa to that occupied by jack 12b in Fig.2. This. rocking of the jacks proceeds in ordinary manner and will generally cause all of the warp threads controlledby' them to passeach other'at about the same pointin the reed shown diagrammatically at R in Fig. 1.

.Asshown herein the regular jacks are located at the rear part of the dobby or near the side plate 14-, but the invention is not necessarily limited to this disposition of the regular jacks.

The matter thus far described operates in usual manner, anyselected jack being moved by outward movement of one or the other of the knives, which may be considered' to, be actuator mechanism; Movement of the jacks in the reverse direction may be effected by return motion of the actuator knife which previously moved them to the left; Fig. 2. If the warp of the loomis room were operated by jacks .12 there would be objectionable crowding of the warp threads at their point of crossing the effect of which might be to abrade delicate warp threads, or produce a sufiicient hesitancy in the shifting of the warp threads to interfere with proper opening of the warp shed. t 1 t I In carrying the present invention into effect provision is madefor operating certain of the. warp lifting harness frames 'in such manner that their threads will cross threads controlled by the regular jackslZ either before or after the crossing'efiected by the regular jacks. In the preferred form of the invention shown in Fig. 3 six similar harness lifting lever units U are shown, but

'only one of them will be described, namely, the one shown in Fig; 2 corresponding to the front harness frame 17.

The lever unit U includes an operating lever 29 which is rockable about and supported by the rod 15 which serves as a primary pivot, and has an open bearing 21 similar to open bearing 16 of the regular jacks. The

operating lever 20 is provided with one of the back levers 10 for actuation by the knives 6 and 7. The operating lever 20- is made in a manner similar to the lower ends of the regular jacks 12 except as will be noted.

'The operating lever has a right hand extension carrying a pivot pin 26 which. passes through plates 27 and 28 of a harness lifter lever designated generally at 29. This lever has an upper part 30 similar to the upper parts of jacks 12 secured to the plates 27 and 28, as by rivets 31, and attached to the harness cord 3 leading to harness frame 17. The harness lever is capable of turning in opposite directions with respect to the operating lever on pin 26, which may be considered a secondary pivot or pivotal support for the harness lever. When the operating lever 20 shown in Fig. l rocks to the left the secondary pivot will move with it around the primary pivot as a center and will lift the harness lever bodily. A reverse movement of the secondary pivot andharness lever occurs when the operating lever returns to the posiends of which are carried by thin plates 43 the left hand 7 ends of which as viewed in FigsJZand 3 are pivoted on the pivot rod 15., The rod .42" and the plates 43 constitute a support means for the rolls capable of being swung around the" pivot rod 15 when desired.

'the bottomof the harness lever. 2'5

In order that the support'tneans may be held normally;

in raised position each of the plates 43 is provided with a pin 45 on which is pivoted the lower end of a link 4-6 the upper end of which is pivoted on a screw 47 tapped into the adjacent dobby plate 13 or 14. The screw 47 is customarily found on many dobbies and cooperates with its pin 45 andthe pivot rod 15 to hold the bar .2 normally stationary so that the rolls 40 will be rotatable on a fixed axis.

in describing the operation of unit U it may be assumed that an operating lever 29 is in its right hand position, Fig. 2, so that the harness lever connected thereto by the secondary pivot will he in down position with the upper end of cam 32 against the roll 4% which registers with it. When the harness lever is in this position its upper end wfll be substantially aligned with'the upper end of lever 12a.

As the operating lever 20 is rocked to the left, Fig. 2,

. around primary pivot 15' the cam 32 will rise from the full line to the dotted line position of Fig. 5 and" as the roll enters the low area 34 it will effect a clockwise turning of the harness lever around its secondary pivot and relative 'to the operating lever. The upper end of the harness lever will therefore move somewhat more slowly than would be the case ifthe levers 20 and 29 were rigid and moved as a jack'12. The jacks which are moving toward the left will therefore be ahead of the harness lever. As the lever 20 continues to turn in a counter-clockwise direction the roll will then engage the other high area 36 which will have the effect of turning the harness lever in a counter-clockwise direction around its secondary pivot and at this'time the upper end of'the harness lever will be movingm'ore rapidly than will be 1 the upper ends of the jacks 121.]

In this preferred form of the invention the first part of the movement of the upper end of harness lever 29 to the left from the position shown in Fig. 2 will be re-' tarded but. the latter part of itsmotion will be accelerated and when the lever 2% has reached its final position, having moved from one extreme position thereof to its other extreme position, the upper ends of the harness lever will be aligned with those jacks 12 which have been moved to the left. The result of the retarded movement of the harness lever is to produce a slow upward motion of its harness frame 17 so that the warp threads controlled by that harness will bersomewhat below the threads controlled by the regular jacks 12 when the latter cross each other in the read dents. The warps controlled by the jacks will then separate and such of them as are moving down will later cross or pass the rising warps of frame 17. Simultaneous crossing of all the warps is thus avoided. V

On'the return motion of lever 20 from the left hand to the right hand position shown in Fig. 2 theroll 40'will pass from higharea 36 toward the low concave area 34 and the harness lever will have an accelerated motion due to clockwise-turning around its secondary pivot. -As -the roll leaves area 34'and is engaged by area 35 angular motion of the harness lever will be reversed and the latter part of its motion will be retarded. In this case the warp threads controlled by lever 29 will be ahead of the warp threads controlled by any of the jacks 12 whichare also moving in a right hand direction, Fig. 2, and the t a order of crossing will be reversed. It will be seen therefore that whether the harness lever is moved to the left, or to the right, the warp threads which it controls will not cross the warp threads controlled by the jacks 12 when the latter threads pass each other. The warp shedis thus effectively split and excessive crowding ofthreads in the reed will be avoided. V

In the first modified formof the invention the parts previously described will be use'd except the cam 54' at the cam has a high'central point 55 convex toward the As shown in Fig. 6

roll 40, a low area 56 above and another low area 57 below the high area 55. This cam is fastened to its harness lever in the same maner as is cam 32 and can be used when it is desired to give the harness lever an accelerated motion in the first part of its movement to the left from the position shown in Fig. 2. It is within the spirit of the invention to use both of the earns 32 and 54 in the same dobby when the warp is usually heavy, in which event at least one of the harness levers will be retarded with respect to the regular jacks and the other harness lever will be accelerated with respect to them.

In the third and fourth forms of the invention the cams and rolls are interchanged with respect to their position. As shown in Fig. 9 the support plates 43 have secured to them a cam member 66 bolted in place as at 61 and replacing the roll rod 42. The harness lever 62 otherwise similar to lever has a roll 63 rotatable thereon between the lever plates 27 and 28. The cam member 60 has a cam part 65 having upper and lower high areas 66 and 67, respectively, and an intermediate concave low area 58. As the harness lever is lifted by operation of the operating lever 20 as viewed in Fig. 8 the roll will first move from high area 67 down into the low area 63 to give the harness lever a clockwise rotation around its secondary pivot, after which continued upward bodily motion of the harness lever by the operating lever will cause the roll 63 to ride up on the high area 66 and give a counter-clockwise rotary motion to the harness lever. This motion will be somewhat similar to that described for the preferred form of the invention and it will be seen that in the first and third forms of the invention the cam is concave toward the roll and has the same general effect on the character of motion of the harness lever.

In the third modified form shown in Figs. 10 and ll the cam member 69 is replaced by a cam member 7% which has a high area 71 intermediate upper and lower low areas 72 and 73, respectively. The cam member 749 is convex toward roll 63 and causes the same character of motion to be imparted to the harness lever as does the convex cam 54.

The fourth modification does not employ either cam or roll but utilizes links 75 which can be pivoted on the rod 42 when the rolls are absent. The outer or right hand free end of each link 75 as viewed in Fig. 12 is pivoted as at 76 to the lower end of its harness lever 77. In the operation of the last form of the invention shown in Figs. 12 and 13 the links will be disposed downwardly when the harness lever is in its right hand position similar to the position shown in Fig. 2. in this position the axis of pivot 76 will be below a line passing through the axis of rod 15 and the fixed pivotal support rod 42 at the beginning of an upward motion of the harness lever. This line is indicated at a-a in Fig. 12. As the operating lever 29 rocks to the left around rod 15 the axis of the pivot 76, which may be considered the point at which the link and lever 77 are pivoted to eacl other, will first move toward the aforesaid line, then cross it, and then move above the line. As the link rises from the position shown in Fig. 12 it will rock the harness lever in a counter-clockwise direction around its secondary pivot, but as the link rises above the line it will then cause a reverse motion of the harness lever and rock it in a clockwise direction around its secondary pivot.

In this fifth form of the invention it is desirable that the parts he so proportioned that the harness lever will be in the same angular position relative to the operating lever at the beginning and end of a continued working stroke of the operating lever. By this relation assurance is given that the upper end of the harness lever 77 will have starting and finishing positions in alignment with the regular jacks.

In all forms of the invention the various mechanisms at the lower end of the harness lever, such as the cam, a roll or the link, form controll means which acts during a continued motion of the harness lever induced by the operating lever to rock the harness lever in opposite directions around the secondary pivot and this rocking motion coupled with the angular motion of the operating lever will cause the harness lever either to be retarded or accelerated at the start of its motion depending upon which form of the invention is used.

As shown in Figs. 2 and 3 the jacks 12 and the operating levers 20 are formed with arcuate slots 50 through which extends a retaining rod 51 supported by the plates 13 and 14. The slots 50 are concentric with the pivot rod 15 and the rod 51 holds the open bearings of the jacks and levers 20 from accidental displacement from the rod 15. If it should be desired to remove either a jack or a lever 20 the screws 47 and rod 51 can be removed so that the support for the rolls 40, or the cam bars 60, 70, can swing from the full line to the dotted line position shown in Fig. 2 in which position the rolls or cams will be in inoperative position relative to the harness levers and out of the path of removal of the levers on rod 15, the direction or path of removal being to the right as viewed in Fig. 2. Because of the fact that the plates 43 are supported from parts which are already present on many dobbies, the invention in any of its forms can readily be added to dobbies now in use.

From the foregoing it will be seen that the invention sets forth means for splitting the shed in a loom dobby comprising an operating lever rockable about a primary pivot, a harness lever movable angularly on the operating lever about a secondary pivot, and control means acting in conjunction with the operating lever to rock the harness lever first in one direction and then in the opposite direction about the secondary pivot during a single continued working stroke of the operating lever. The control means can be made to rock the harness lever at the start of its motion either with an accelerated or a retarded motion relative to the motion of the regular jacks. During the stroke of the operating lever the control means causes the harness lever to move at a variable rate different from that of the regular harness jacks. The harness levers will align with the regular harness jacks when the latter are in either of their extreme positions and for this reason the extent of motion of their harness francs, such as frame 17, will be the same as though regular jacks were used. When a cam member forms part of the control means it may be on either the harness lever or on the dobby, and may be either convex or concave toward its roll member. Two harness levers may have their cams one convex and the other concave so that the group of warp threads controlled by the harness levers can be one ahead and the other behind the groups of threads controlled by the regular jacks. The fifth form of the invention employs a link one end of which rocks about a stationary pivot and the other end of which is pivoted to the harness lever, the link being so disposed as to cause the harness lever to rock first in one direction and then in the opposite direction about the secondary pivot during a single continued working stroke or" the operating lever. Furthermore, part of the control means can be mounted on a carrier which can be swung down to facilitate removal of a jack or operating lever. The operating lever 29 may not be necessary in all uses to oh the invention can be put, since it will be suiiicient if an operating member t necessarily a lever moves the harness lever bodily with respect to the control means. While the link 75 has been shown as pivoted around an axis between the pin 15 and the harness lever, it

need not necessarily be thus pivoted, since the link would operate it it were pivoted beyond the harness lever with reference to pin 15.

Having now particularly described and ascertained the nature of the invention and in what manner the same is to be performed, what is claimed is:

l. in a dobby for a loom having a harness frame, an

operating lever mounted on the dobby for pivotal movement with respect thereto, actuator mechanism effective during loom operation to give the operating lever an angular movement from one extreme position thereof to another extreme position thereof, a harness lever pivoted to the operating lever'operatively connected to the harness frame and having a bodily movement imparted to the operating lever during a later part of. said angular movement of .the operating lever.

2. The structure set forth in claim 1 wherein said control means includes a cam on the harness lever, and a roll to engage the. cam rotatablejabout an axis normallyfixed with respect to the dobby.

3. The structure set forth in claim l'wherein said control means includes a cam normally in fixed position with respect to the dobby and a roll on the harness lever for engagement with thecam.

4. The structure set forth inclaim 1 wherein said control means includes a roll member and a cam member, one member being on the harness lever and the other member being on the dobby.

'5. The structure set forth in claim 4 wherein the cam member is convex toward the roll member.

' 6. The structure set forth in claim 4 wherein the cam member is concave toward the roll member.

7; The structure set forth in claim 4 wherein said operating lever is removable from the dobby in a path directed toward said members and said other member is mounted on a support normally fixed with respect to, the dobby but movable thereon to move said other member to a non-operating position out of said path to facilitate removal of the operating lever.

8. The structure set forth in claim 7 wherein the dobby has a pivot rod on which the operating lever turns and said support is pivoted to said pivot bar and. a link supported by the dobby normally cooperates with said pivot bar to hold the support stationary in position to locate said other member for engagement with said one member.

7 9. In a dobby for a loom having a harness frame, actuator mechanism, means constituting a primary pivot,

an operating lever mounted on said pivot to be given an angular movement about the latter from one extreme position to another extreme position by the actuator means, a harness lever operatively connected to the harness frame, a secondary pivot connecting said levers causing the harness lever to move bodily when the operating lever has said angular movement, and control means for the harness lever dependent for operation thereof upon said angular movement of the operating lever and effective during the first partof said angular movement of the operating lever to rock said harness lever in one direction around said secondary pivot and thereafter during a later part of said angular movement of the operating lever effectrocking of the harness lever in the opposite'direction around said secondary pivot.

10. The structure set forth in claim 9 wherein one end of the harness lever is operatively connected to the harness frame and said control means is at the other end of the harness lever and said secondary pivot is intermediate'the ends of the harness lever.

ll. The structure set forth in claim 9 wherein said and in said later part of said angular movement effects rocking of the harness lever in said opposite direction around said secondary pivotas said. link swings around said fixed pivotal support thereforv 12. The structure set forth in claim 9 wherein said control mechanism includes a link having one end thereof rockable about a fixed pivotal support and having the other end thereof pivoted to the harness lever at a.

point normally at one side of a line passing through said primary pivot and said fixed pivotal support for the linkwhen the operating lever is in an extreme position thereof, the operating lever when moving to the other extreme position thereof causing said pointfirst to move toward said line, then cross the line, and thereafter move to the opposite side of said line.

13. A harness lever unit for a loomdobby having control member and a primary pivot and operating with a harness frame, said unit comprising an operating lever for mounting on said primary pivot, a harnesslever having one end thereof adapted for operative connection to r the harness frame, asecondary pivot connecting the. op-

erating and harness levers around which the latter can be rocked with respect to the operating lever, and means on the. other end of the, harness lever for engagement with said control member by which the harness lever can be rocked with respect to the operating lever about said secondary pivot.

14. The unit set forth in claim 13 wherein said means on the harness lever is a cam. V

15. The unit set forth in claim 13 wherein said means on the harness lever is a roll.

16. The unit set forth in claim 13 wherein said means on the harness lever comprises a link pivotally connected to the harness lever.

17. In a dobby for a loom having a harness frame to be moved during a shedding operation of the loom, a harness lever operatively connected -at one end thereof to the harness frame, a pivotal support for the harness lever intermediate the ends of the latter, actuating means to give said pivotal support a movement'incident to a shedding operation of the loom, and control means acting on the other end of the harness lever causing the latter to roclcfirst in one direction around said pivotal support and thereafter rockin the opposite direction around said pivotal support during said movementof said pivotal support by the'operating means.

18. In a dobby to split the Warp shed of a loom having a plurality of warp harness frames and operating with actuator mechanism, pivot means extending across the dobby, a plurality of harness jacks operatively connected to certain of the haIness frames and mounted on said pivot means for turrdng thereof, a plurality of operating levers also mounted on said pivot means for turning thereon, harness levers, one for each operating lever,

pivoted to the latter and operatively connected to other said pivot means and being rockable on its operating lever, and control means'for each harness lever to determine the character of motion of the harness lever when the latter is moved bodily by its operating lever, said actuator mechanism during a continued operation thereof causing said jacks and operating levers to. turn on said pivot means with given characters of motion and reach the mid-position of their movements at substantially the .same given time and said control means acting dependently upon movement 'of the operating levers to cause said harness levers to reach said mid-position of said jacks and operating levers at a time other than said given time.

19. In a dobby for a loom having a harness frame, an operating member having a movement from one extreme position thereof to another extreme position thereof in the operation of the dobby, a harness lever pivoted to. the member operatively connected to the harnessframe and having a bodily movement imparted thereto by the member when the latter has said movement thereof, during a later part of said movement of the operating and control means for the harness lever efiective due to member.

bodily movement of the latter caused by said movement of the operating member from one to the other of said Refeggnce Cit d i th file f thi patent extreme positions thereof to rock the harness lever in 5 one direction with respect to the operating member dur- UNITED STATES PATENTS ing the first part of said movement of the operating mem- 680,181 Staubli Aug. 6, 1901 her and effect rocking of the harness lever in the op- 1,682,791 Malloy Sept. 4, 1928 posite direction with respect to the operating member 2,6 ,438 Pfarrwaller July 7, 1953 

